1. Field of the Invention
The present invention relates generally to drum-cutter mining machines, and, more particularly, to a mining machine containing a housing assembly housing connecting gears which connect the mining machine to a drive wheel which engages with a rack or chain affixed to a longwall conveyer.
2. Description of the Prior Art
Conventional longwall mining procedures typically utilize drum-cutter mining machines to shear a mineral from a mine wall, such mineral being transported on a longwall conveyer which extends along the length of the mine wall. The drum-cutter mining machine includes at least one, and usually two circular cutting drums which extend from opposite ends of the mining machine.
The drum-cutter mining machine is translatable along the length of the mine wall face by engagement of the mining machine with a pinwheel rack structure affixed to the longwall conveyer. A drive wheel of the mining machine meshingly engages with the rack structure to transmit feed forces to allow translation of the mining machine therealong.
One such drum-cutter mining machine is disclosed in a brochure entitled "Doubled Ended Ranging Drum Shearer" of Mining Supplies Limited No. 1180/19, page 7. The mining machine disclosed therein contains a capstan position on a coal-face side (i.e. mine wall face side) of a longwall conveyer, and contains a capstan housing which covers the output shaft butt of a drive motor supported in the capstan with the housing extending along the capstan as far as the plane of the rack structure. Positioned within the housing are spur gears which meshingly engage with the output shaft butt of the drive motor and which also meshingly engage with the drive wheel. The drive wheel, in turn, engages with the rack structure to allow translation of the mining machine therealong. The drive wheel is positioned outside of the housing, is axially to a spur gear, and the housing may be connected to the sidewall of the capstan and any of various swiveling positions.
Also disclosed in the prior art is West German Patent No. DE-PS 2935643 which discloses a substructure for a mining machine wherein the height of the substructure is adjustable. The substructure also carries drive wheels above the rack structure. Wheel cases may also be affixed with the bearings for the drive wheels at varying heights of the substructure of the machine.
Further, West German Patent No. DE OS 2925240 discloses a drum-cutter mining machine which includes a machine frame having at least one end plate which is provided with a drive wheel wherein the drive wheel may be connected to the machine frame in any various height positions. The end plate, which is U-shaped, is positioned such that the two ends thereof rest against the machine frame, thereby enclosing the drive wheel. The drive wheel meshingly engages with an intermediate gear wheel which is positioned to rotate in conjunction with rotation of an output shaft butt of the drive motor supported in the capstan. Several groups of bores extending into the machine frame allow the end plate to be fastened to the machine frame, and the drive wheel supported thereby, in any of various height positions to thereby set the drive wheel at a desired height to allow engagement with the rack structure.
In most instances, the drive wheel which engages with the rack structure contains teeth members to allow meshing engagement with the reduction gears. On the drive wheel side facing the mining machine, the drive wheel is enclosed by a plate member carrying the forces exerted on the drive wheel, and is swivelably mounted about the axis of the reduction gears of the capstan, and may be fixed in various swivelling positions, in order to allow the drive wheel to engage with the rack structure at a desired height (see, for example DE-PS2714532).
Because the drum-cutter mining machines utilized in longwall mining operations are quite heavy, the feed forces required to rotate the drive wheel to allow translation of the mining machine along the rack structure is commonly quite high, and, in some instances, may reach or exceed 300 kilonewtons. A stable and torsionally rigid of wheel support affixed to the sidewall of the capstan housing is therefore required in order to prevent individual teeth members of the drive wheel from fracturing during translation of the mining machine. Also, the high feed forces causes wearing of the drive wheel, thereby requiring frequent replacement of the drive wheel.
Also as result of the high feed forces, the reduction gears connecting the drive wheel to the drive motors must be frequently lubricated.
Therefore, the mining machine design must allow for quick replacement of the drive wheel, and, further, the reduction gears must be encapsulated in a fluid-tight compartment.
It is therefore the object of the present invention to provide a drum-cutter mining machine construction which allows for quick replacement of the drive wheel.
It is a further object of the present invention to provide a drum-cutter mining machine which allows the position of the drive wheel relative to the mining machine to be altered to allow use of the mining machine on various rack structure assemblies.